Floor panel and method for manufacturing a floor panel

ABSTRACT

Floor panel, whereby this floor panel ( 1 ) comprises a decor ( 10 ), as well as a top layer ( 11 ) on the basis of synthetic material ( 12 ), and whereby the upper side ( 2 ) of the floor panel ( 1 ) imitates slate or another flaky kind of stone, characterized in that the floor panel ( 1 ) comprises terrace-shaped impressions ( 18 ) at its upper side ( 2 ).

This invention relates to a floor panel, as well as to a method for manufacturing such floor panel.

More particularly, the invention relates to a floor panel of the type mostly called laminate panel.

It is known that such floor panel can be of varying construction. Mostly, such floor panels comprise at least a substrate, a printed decor, as well as top layer on the basis of synthetic material.

It is also known that such floor panels can be applied for forming a floating floor covering. Hereby, these floor panels, during installation, are coupled at their edges, either by means of a classical tongue and groove connection, whereby these possibly are glued into each other, or by means of a mechanical coupling providing for a mutual locking of the floor panels in horizontal as well as in vertical directions, for example, as described in the international patent application No. WO 97/47834. This patent document also describes a possibility for manufacturing such coupling means. Hereby, in the machining operation, the edge of the upper side of the floor panel is used as a reference plane.

From the patent application No. WO 01/96689, it is known to provide, by means of a press treatment with a structured press plate, impressions in the transparent top layer, whereby these impressions imitate a wood structure, such as wood pores and wood knots. Hereby, the applied impressions may follow the printed wood decor, with the intention of rendering the imitation more realistic. In the case of such wood imitation, the impressions are restricted to small impressions embossed at a substantially constant depth.

The present invention has as an aim to imitate, with a floor panel of the above-mentioned type, a flaky kind of stone, in particular flaky natural stone, for example, slate, in a realistic manner.

To this aim, the invention, according to its first aspect, relates to a floor panel, whereby this floor panel comprises a decor, as well as a top layer on the basis of synthetic material, and whereby the upper side of the floor panel imitates slate or another flaky kind of stone, with the characteristic that the floor panel comprises terrace-shaped impressions at its upper side.

By “terrace-shaped impressions”, impressions have to be understood having at least two step-wise transitions in the same direction, either downward or upward, between substantially continuously impressions, further indicated as “terraces”. The application of such impression offers a technical solution improving the realistic appearance of a floor panel imitating a flaky kind of stone. Namely, such terrace-shaped impressions do form a technical means, due to which flakes lying on top of each other, the lowermost of which partially projects from under the uppermost, can be imitated very true to nature. The terraces then imitate, for example, each in its turn a visible portion of a flake, whereas the step-wise transitions in the terrace-shaped impressions imitate the transition between each two successive flakes.

It is noted that, although these impressions substantially are provided in a mostly transparent top layer of synthetic material, contrary to all expectations, such terraces are clearly perceptible and therefore the flaky structure to be imitated is underlined in an optimum manner.

Preferably, the deepest impressions will be less deep than the largest thickness of the top layer, still better they will be less than 350 μm deep. Deeper impressions, however, are not excluded. These may even continue up into the underlying substrate.

Globally, the decor may show substantially only one color. In the case of imitating slate, this may be, for example, black or gray, although other colors, amongst which light-tinted colors, are not excluded.

Preferably, however, the decor represents a pattern that is realized in function of the kind of stone to be imitated, whereby then mostly indeed several colors and/or tints of a color are applied. More particular, it is preferred that the pattern is formed by an image of the flaky kind of stone to be imitated.

In the latter case, one may start, for example, from a real slate or other flaky kind of stone, of which the image is reproduced, for example, by scanning it. When scanning or such, colors as well as height differences can be stored. These data do form, after a possible processing thereof, for example, in order to compensate paper shrinkage, the basis of the pattern of the printed decor and the design of the press plate. Neither is it excluded, according to the present invention, to construct an image for the decor and/or to determine the structure for the impressions, more particularly the aforementioned terrace-shaped impressions, and possible other impressions in an artificial manner. Of course, it is also possible to form a combination of, on the one hand, data obtained starting from a real example of a flaky kind of stone and, on the other hand, data constructed artificially.

The decor preferably is realized by means of a printing technique.

The possible addition of dark shadow lines and/or transition lines on the decor, where height differences occur in the natural material, is advantageous for the imitation. Hereby, the shadow lines and/or transition lines follow at least partially the contour of one or more imitated flakes.

In a preferred form of embodiment of the invention, the terrace-shaped impressions are at least partially corresponding to the pattern of the decor. In this case, some, and preferably more than 50% of the transitions between flakes represented in the decor show a corresponding step-wise transition in the terrace-shaped impressions of the top layer. In this case, the terraces formed thereby will coincide at least partially with the visible portions of the flakes depicted in the pattern of the decor.

In a particular form of embodiment, shadow lines and/or explicit transitions are represented in the pattern and are the terrace-shaped impressions at least partially applied in correspondence to these shadow lines and/or transition lines. The presence of a shadow line or transition line in the pattern at the location where a step-wise transition is present in the terrace-shaped impressions, enhances the natural appearance of the imitation of a flaky kind of stone. Within the scope of the invention, it is clear that the floor panel may also comprise shadow lines having no corresponding impression in the top layer.

According to a first possibility of the invention, the terrace-shaped impressions will comprise terraces, which are substantially situated in planes that are substantially parallel to the plane in which the floor panel extends, whereby these terraces form zones that are realized from terrace to terrace at a different depth.

Such terrace-shaped impression can be obtained as the result of a press treatment with a press plate, which has obtained a terraced surface by means of several etching treatments, for example, at least five and still better at least eight etching treatments. Preferably, partially overlapping portions are etched into the press plate, and still more preferably, these etching treatments in their turn are realized with different etching depths. The use of such press plate for producing the terrace-shaped impressions provides for that the number of different heights at which impressed terraces are located on the floor panel, is larger than the number of etching treatments performed on the press plate. In order to fully take advantage of this specific technique, it is preferred that the overlapping areas are chosen at least such that in one and the same floor panel at least the double amount of height levels are present than etching treatments have been applied in the corresponding portion of the press plate.

A method for manufacturing a floor panel, where such press plate has been applied, offers a broad range of new possibilities for designing surface structures, more particularly surface structures matching printed decors that represent natural materials, such as natural stone. Therefore, the invention also relates to a method for manufacturing a floor panel, of the type that is intended for forming a floating floor covering, whereby this floor panel consists of a basic board with at the upper side a top layer on the basis of synthetic material, with impressions, with the characteristic that the impressions are applied during a press treatment with a press plate on which at least five and still better at least eight etching treatments have been performed, at least a number of which in their turn have been performed with differing etching depths and at least a number have been performed partially overlapping. It is clear that this method is not restricted to the imitation of flaky kinds of stone.

Of course, such terrace-shaped impressions may also be obtained as a result of a press treatment, whereby the press plate is manufactured in another manner than described herein above. Also, such terrace-shaped impressions can be realized as a result of a treatment other than a press treatment, for example, by systematically depositing synthetic materials to obtain a terraced construction.

According to a second possibility of the invention, the floor panel comprises terrace-shaped impressions that are formed by successive terrace-shaped step-wise transitions, whereby the surface of the zones lying in between as such changes in height, such that the height difference between two successive terrace edges is smaller than the height difference at the location of a transition, and preferably is zero or almost zero. A floor panel with such impressions has the same desired appearance of terrace-shaped impressions, as well as the same tactile structure, and moreover has the advantage that more step-wise transitions can be realized in a top layer of the same thickness. Such technique for manufacturing a laminate panel imitating a flaky kind of stone is advantageous in view of the fact that preferably the deepest impression is smaller than the largest thickness of the top layer, and even better is smaller than 350 μm. If desired, consequently the top layer for the same impressed structure also can be made thinner, for example, by forming it of a less thick layer of resin.

Other possibilities for realizing the aforementioned terrace-shaped impressions are not excluded.

Also, it is clear that within the scope of the invention, terrace-shaped impressions according to the aforementioned first possibility can be combined with terrace-shaped impressions according to the aforementioned second possibility in one and the same floor panel.

Within the scope of the invention, it is also possible that the laminate panel additionally, either over its entire surface, or over only a part thereof, for example, in several terraces, comprises impressions that imitate the surface texture of a natural stone, more particularly imitate a surface texture usually occurring on a visible portion of a flake of real stone.

According to a particular form of embodiment, the floor panel of this invention comprises several gloss degrees. Preferably, it has at least two zones of different gloss degree, whereby each of these zones substantially corresponds to a visible portion of a flake of the imitated kind of stone. Preferably, at least the entire or almost entire surface of one or more terraces is matte, whereas the entire or almost entire surface of other terraces then is relatively glossy. The use of different gloss degrees causes the optical illusion that the matte impression seems deeper than it really is. By making a number of terraces matte, the number of optically “perceived” height differences on the floor panel can be increased, whereas the real number of height differences remains restricted. In this manner, by a press treatment by means of a press plate that is etched a restricted number of times and is rendered matte on some places, still a realistic result, with a visual impression of several height differences in the imitated kind of stone, can be achieved.

It is clear that, without leaving the scope of the invention, also additional impressions can be realized in the top layer of the floor panel by means of the press plate, for example, impressions imitating a joint. Also, it is possible to realize the different characteristics of the surface of the flaky kind of stone by means of different press treatments, for example, a press treatment providing the difference in gloss degree and the surface texture, and a subsequent press treatment providing the terrace-shaped impressions. Also, it is possible that the aforementioned structure or certain portions thereof can be obtained in another manner than by means of a profiled press plate, for example, by means of a structured foil, a profiled roller, and so on.

In order to further enhance the feeling of authenticity during installation, a basic board or substrate can be provided with a color matching the imitated kind of stone. In the case of MDF (Medium Density Fiberboard) or HDF (High Density Fiberboard), this is possible, for example, by coloring the basic board with a color component and/or by coloring the profiled edges entirely or almost entirely. In this manner, a floor panel imitating slate can be provided with a MDF or HDF basic board, which is colored with a black-gray color component.

The imitation of the flaky kind of stone preferably will continue over the entire floor panel, possibly with the exception of the edges. At the edges, a joint can be imitated. However, the invention does not exclude that several tiles are represented on one floor panel, which tiles possibly are separated from each other by an imitation of a joint. The shape of the floor panel basically can be chosen freely, however, preferably the floor panel is rectangular, either oblong or square. Also, the size of the floor panel can be chosen freely. So, for example, relatively small floor panels with all sides smaller than 20 cm are possible, as well as large floor panels with two or more sides larger than 40 cm. Other dimensions are, of course, not excluded. A particularly useful tile format when imitating flaky kinds of stone, more particularly slate, is in the order of magnitude of 40×40 cm, in consideration of the fact that these dimensions in practice also are the most merchantable for real flaky natural stone.

For one and the same floor covering, preferably several tiles with different patterns are produced, for example, with more than five and even better at least nine patterns, whereby tiles with different patterns are packaged in a mixed manner, such that there are different patterns in one package of floor panels, whereby automatically a good mixture is obtained when installing the floor covering.

According to a preferred form of embodiment of the invention, the floor panel comprises, at one or more edges, preferably at least at two opposite edges, and still better at all edges, cut-away edge portions, such as, for example, bevels. The surface obtained by the cut-away edge portions may or may not be colored. This can be realized, for example, by means of a covering provided on the surface, for example, by means of transfer printing. The surface can also be provided with a color by direct coloring with a coloring agent, such as a coloring agent applied by means of a felt-tip pen or by means of impregnation, a lacquer, a paint, or the like. The coloring either can be matched to the color of the imitated kind of stone or not. In the case of a coloring with a matched color, such cut-off edge portions imitate the small rounding always present at the edges of real natural stone tiles. In the case of the floor panels of this invention, they can be applied solely in order to provide a more truthful representation or in order to imitate, for example, a small joint. In both cases, the size of the cut-away portion in horizontal direction best will be smaller than three millimeters, and even better smaller than two millimeters. The size of the cut-away portion in height is preferably at least one millimeter. Also, the color can be chosen such that it imitates a filled joint, such as a groutline.

When the coloring of the obtained surface also continues downward up to over the edge of the cut-away portion, it is prevented that, due to a possibly faulty height alignment of adjacent floor panels, the material of the basic board becomes visible in a disturbing manner.

In order to enable the installation of the floor panel of this invention in a floating floor covering, the floor panel comprises coupling means preferably at least at two opposite edges. In the case of a rectangular or square floor panel, it preferably comprises coupling means at all four edges. These coupling means preferably provide for a locking in vertical and horizontal directions.

When forming these coupling means, usually the edge of the upper side of the floor panel is used as a reference for the machining treatment, in view of the fact that the floor panel is required to have its upper side perfectly adjoin to the upper side of all adjacent floor panels in the floor covering. With the fact that the upper side is used as a reference plane, is meant that the floor panel, during the shaping of the coupling means, is moved with its upper side along a reference plane, such as a sliding shoe, the position of which is adjusted in function of the cutting tools established along it. In order to prevent that the location of the coupling means along the edge at which they are present varies in height in respect to the basic board, it is preferred that the differences in height occurring along the upper edge of the floor panel as a consequence of the terrace-shaped impressions, are restricted to zones smaller than 10 cm, as measured along the edge of the floor panel. This means that an impressed zone along an edge of the floor panel, according to this preferred form of embodiment, never extends over a length of more than 10 cm, such that the floor panel, during the shaping of the coupling means, always is supported by the aforementioned sliding shoe or the like at its highest or almost highest points of its upper edge. In the known embodiments, such sliding shoe is of such length that impressions over lengths of less than 10 cm will not be felt at a floor panel moving along such sliding shoe, with as a result that the aforementioned impressions have no disadvantageous effect on the straightness of the profile of the coupling means along the edges of the floor panels. In this manner, a disadvantageous factor is excluded or minimized, namely the non-straightness of said profiles, which, as known, may render the coupling of such floor panels to each other difficult.

In general, it is noted that coupling means, the location of which along the edge where they are located varies in respect to the basic board, as aforementioned, may lead to difficult coupling and bad adjoining of floor panels in a floor covering. Therefore, it was always assumed that the length of impressions varying along the edges of the floor panels always had to be kept restricted. Indeed, it is so that, when this is taken into account, as aforementioned a disadvantageous factor is excluded and minimized. However, contrary to all expectations, the inventors have found that this disadvantageous factor, which preferably still shall be avoided, in fact is less detrimental than always thought up to now. Thus, this means that also along the edges impressed zones varying in depth can be created along the edges, said zones extending over a larger distance than 10 cm along the respective edges. On one hand, this indeed may render the mutual joining of floor panels difficult to some extent, however, according to the present invention it does not form a real problem. On the other hand, in fact the freedom of design possibilities is enhanced, whereby, for example, also more true to nature imitations can be realized, in view of the fact that now it was found that the criteria for performing impressions along the edges of a floor panel are less stringent than presumed up to now. It is clear that the unexpected possibility of providing impressions over such distances along the edge, enhances the natural appearance of floor panels imitating flaky kinds of stone. So, for example, starting from this fact, for example, terrace-shaped impressions can be performed along the edge of a panel that extend from the beginning to the end of an edge, globally seen, downward-inclined in one direction.

This unexpected effect, in other words, the fact that floor panels with non-straight and/or downward-inclined coupling means, more particularly coupling parts, still can be interconnected in a relatively smooth manner, may also be applied in floor panels having other patterns and structures than for imitating flaky kinds of stone, in which, for what reasons whatsoever, also along one or more edges impressed zones are present, which, when providing the coupling means, cause a fluctuation in the height of these coupling means in respect to the substrate. Consequently, the invention, according to a second independent aspect, also relates to a floor panel, of the type that is intended for forming a floating floor covering, whereby this floor panel comprises a single-layer or multi-layer or single- or multipartite substrate, a decor, as well as a top layer on the basis of synthetic material, with the characteristic that impressed zones are present on the upper side of the floor panel, said zones extending along at least a part of at least one upper edge of the floor panel and that the floor panel, at least at the edge where said upper edge is situated and at an opposed edge, is provided with mechanical coupling means allowing to couple two of such floor panels to each other, which coupling means thereby can effect a locking in vertical and horizontal directions; and that these coupling means are the result of a machining treatment, whereby the upper side of the floor panel is used as a reference, whereby the location of the coupling means as a result of the impressed zones fluctuates in height in respect to the substrate.

Even with a fluctuation of more than 0,2 mm in height, it was unexpectedly found that the floor panels still can be interconnected in an effective manner.

According to the second aspect of this invention, the floor panel, at the upper edge, can be provided with a cut-away edge portion that is colored, such as a beveled edge. Hereby is obtained that possible differences in height between the substrates and top layers of coupled-together floor panels are less perceptible. Masking the bad adjoining of floor panels can also be obtained by using a basic board with a color matching the imitated kind of stone, instead by means of a cut-away edge portion.

According to a third and last aspect, the invention also relates to a floor panel, of the type intended for forming a floating floor covering, whereby this floor panel comprises a single-layer or multi-layer or single- or multipartite substrate, a decor, as well as a top layer on the basis of synthetic material, and whereby this floor panel, at least at two opposite edges, is provided with mechanical coupling means allowing to couple two of such floor panels to each other, whereby these coupling means can effect a locking in vertical and horizontal directions, with as a characteristic that at the upper side of the floor panel at least one impressed zone is present that is situated along an upper edge of at least one of the aforementioned two opposite edges of the floor panel; that this impressed zone shows an impression which, at least in the upper edge, effects a height difference with as the largest value at least 0,1 mm; and that this impressed zone extends along said upper edge over a distance of at least 10 centimeters. In view of the fact that the inventors unexpectedly found that a floor panel with the characteristics of this third aspect, for engaging and adjoining two of such floor panels, has less detrimental consequences than presumed up to now, the possibility of nevertheless manufacturing such panels and coupling them relatively smooth with a relatively good adjoining, opens a broad range of new design possibilities.

It is clear that here, too, the application of a cut-away edge portion at the upper edge offers the already mentioned advantages.

According to each aspect, various other preferred forms of embodiment of the invention are possible. To this aim, reference is made to the detailed description and appended claims.

With the intention of better showing the characteristics of the invention, hereafter, as an example without any limitative character, several preferred forms of embodiment are described, with reference to the accompanying drawings, wherein:

FIG. 1 is a schematic representation of a floor panel according to the invention;

FIG. 2, at a larger scale, represents a cross-section according to line II-II in FIG. 1;

FIG. 3 represents in cross-section how two of such floor panels can be coupled to each other;

FIGS. 4 and 5, strongly schematized and enlarged in height, represent the portion indicated by F4 in FIG. 2, for two variants;

FIG. 6, at a larger scale, represents a variant for the portion indicated by F6 in FIG. 4;

FIG. 7, in top view, represents a possible embodiment of the portion indicated by F7 in FIG. 1;

FIGS. 8 to 11 show schematic representations in connection to methods for manufacturing floor panels according to the invention;

FIG. 12 represents an enlargement of the portion indicated by F12 in FIG. 3;

FIG. 13, at a larger scale, represents the portion indicated by F13 in FIG. 2;

FIGS. 14 and 15 represent views analogous to that of FIG. 13, however, for two variants;

FIGS. 16 and 17, in a schematic manner, represent a possible form of a cross-section according to line XVI-XVI in FIG. 2.

FIG. 1 is a strongly schematized representation of a tile-shaped floor panel 1 according to the invention. The upper side 2 of the floor panel 2 imitates the typical structure of a flaky kind of stone. The represented imitated structure relates to a slate structure, which is determined by portions 3 imitating flakes lying on top of each other, whereby the lowermost project only partially from below the uppermost, whereby the transitions 4 between the portions 3, as will be explained below, can be made more clearly perceptible at least by means of a relief in the upper side 2.

As represented in FIGS. 2 and 3, the floor panel 1, at least at two opposite edges 5A-6A, is provided with coupling means, more particularly coupling means 7-8, which, in coupled condition, effect a locking in horizontal and vertical directions. Preferably, also at the other edges, in this case, the edges 5B-6B, coupling means are present that can effect a locking in horizontal and vertical directions, which means either can be made identical to the coupling means 7-8 or not.

As represented in FIGS. 2 to 4, the floor panel 1 comprises a substrate or basic board 1, a preferably printed decor 10 and a top layer 11 of synthetic material 12.

The substrate 9 preferably consists of a board on the basis of wood, such as fiberboard or particle board, more particularly MDF or HDF. Also, it is not excluded that such substrate 9 consists of other materials, for example, of synthetic material. Also, such substrate as such can be composed of several parts and/or layers.

The represented floor panel 1 is of the DPL type (Direct Pressure Laminate), which means that the aforementioned top layer 11 is directly pressed onto the substrate 9.

Hereby, the top layer 11, at least in the represented example, consists of a so-called decor layer 13 and overlay 14. The decor layer 13 is formed of a resin-impregnated carrier 15, such as a paper web, upon which the printed decor 10 is present in the form of a print. The overlay 14 is also formed of a resin-impregnated carrier 16, which preferably also consists of paper or the like and is of such nature that the carrier becomes transparent after pressing. The resin of the decor layer 13 and the overlay 14 form the aforementioned synthetic material 12 of the top layer 11.

At the underside of the substrate 9, in a known manner a backing layer 17 can be present.

FIG. 4 represents the terrace-shaped impressions 18, which, in accordance with the present invention, are present in the top layer 11 of the floor panel 1. It is noted that the depth of the terrace-shaped impressions 18 is represented in a strongly exaggerated fashion. Whereas the represented cross-section running according to the line II-II in FIG. 1, in width direction comprises an entire floor panel with as preferred dimensions 40×40 cm, the here represented impressions 18 in reality have a maximum depth of, for example, 350 μm. The exaggerated representation has the purpose of enabling a better description of the geometry of the terrace-shaped impressions 18.

In the form of embodiment of FIG. 4, the terrace-shaped impressions 18 are characterized by substantially flat zones that form terraces 19 and that are separated by step-wise transitions, in particular the aforementioned transitions 4. In this case, the impressions 18, and more particularly the terraces 19, are substantially parallel to the plane in which the floor panel 1 extends. From terrace to terrace, the depth of the impression 18 changes. In FIG. 4 is also represented that not only the overlay 14, but possibly the decor layer 13, too, can be impressed as a result of the impressions 18.

It is noted that in FIG. 4, as well as in the other respective figures, the carriers 15 and 16 are represented only schematically, and that these in reality shall not necessarily be deformed in the illustrated manner.

FIG. 5 represents a view similar to that of FIG. 4, however, for a variant. The represented impressions 18 herein are formed by successive step-wise transitions 4, whereby the surface of the zones 20 lying in between and forming the terraces 19 as such varies in height, such that the difference in height between two successive terrace edges 21, which thus form the transitions 4, is smaller than the difference in height at the location of a transition 4, and preferably is zero or almost zero. This latter means that the terrace edges 21 represented in FIG. 5 all are situated in the same or almost the same plane 22.

The embodiment of FIG. 5 allows to perform the impressions 18 less deep, whereas per transition 4 still the same step-wise step or even a larger step-wise step than at each transition 4 in FIG. 4 can be applied.

FIG. 6 shows that the terrace-shaped impressions 18 further can also be combined with a relief 23 imitating a surface texture in the terraces, in this case, 19, and/or that certain ones of the terraces 19 can be provided with a matte-rendering relief 24, such that the surface shows terraces 19 of different gloss degree. Of course, various combinations are possible. The reliefs 23 and 24 either can be applied in the same floor panel and/or in the same terrace or not. Further, all this is also possible in any form of terrace-shaped impressions 18, thus with embodiments according to FIGS. 4 and 5, as well as with other possible embodiments.

FIG. 7 shows, in top view, an embodiment, whereby the terrace-shaped impressions 18 are corresponding to the pattern of the printed decor 10, which here is printed in function of the imitated kind of stone. The step-wise transitions 4 of the terraces substantially are situated at the location where the decor 10 represents a transition between two flakes. Hereby, the successive flakes are schematically represented in FIG. 7 by means of different hatchings.

As also represented in FIG. 7, at the height of one or more transitions 4, more particularly next to one or more of the transitions 4, also a shadow line 25 can be represented in the decor 10.

A possible method for manufacturing a floor panel 1 according to the invention is represented in FIG. 8. This relates to a floor panel of the type that, as already described in respect to FIG. 4, comprises a basic board 9 of MDF, a in this case printed decor layer 13, an overlay 14 and a backing layer 17. Hereby, this basic board 9 and all other layers are compressed in a heated press 26, whereby a consolidated whole is created. As in the press 26, a press plate 27 is applied that comprises projections 28, which substantially are the negative of the aforementioned impressions 18, after pressing a surface is obtained having the aforementioned terrace-shaped impressions 18.

It is noted that by means of such press treatment, in reality mostly a larger consolidated board is realized, namely a board with a typical dimension of, for example, 2×5,5 m, which subsequently is cut to form several floor panels 1. The possible coupling means 7-8 then are provided per floor panel by means of a milling treatment at the edges 5A-5B-6A-6B thereof.

In order to minimize the risk of porosity occurring in the top layer at the height of the transitions 4, it is preferred that pressures are applied that are higher than 70 bar, and still better are at least 77 bar.

If a coincidence between the pattern of the decor 10 on the decor layer 13 and the terrace-shaped impressions 18 is required, at least the decor layer 13 and the press plate 27 must be precisely aligned in respect to each other. To this aim, several possibilities are known, such as, for example, providing marks on the decor paper, such that a positioning under the press is possible.

FIGS. 9 and 10 illustrate a particular technique for realizing a press plate 27 for manufacturing a well-defined form of embodiment of a floor panel 1 according to the invention. To this aim, FIG. 9 represents a press plate 27, which has been etched a first time over a zone Z1 with a depth E1. FIG. 10 shows the result of a second etching treatment on the same press plate 27. The second etching treatment is performed over a zone Z2 partially overlapping the zone Z1 of the first treatment. The second etching treatment is continued up to a depth E2 differing from E1. From FIG. 10, it is clear that by means of these etching treatments, three different depths have been obtained in the press plate, namely the depth E1, E2 and E3, the latter being the sum of E1 and E2. Together with the initial level, the two etching treatments result in four different levels in the press plate. Generally, it can be stated that by means of n etching treatments of different depth that partially overlap each other, 2^(n) different levels can be obtained.

FIG. 11 shows in a schematic manner that after the press treatment with the obtained press plate 27 of FIG. 10, a relief can be obtained in the top layer 11 of a floor panel 1, with terraces 19 that also are situated on different levels.

In order to minimize the risk of an adhesion between the press plate 27 and the synthetic material 12, possibly a so-called “release” paper can be provided in between them.

FIG. 12 shows two coupled floor panels 1, of which the terrace-shaped impressions 18 extend up to the edge of the floor panels 1. From FIG. 12, it is clear that hereby, due to the presence of the impressions 18, differences in height may be created, more particularly an edge 29 can be formed, which possibly is experienced as disturbing. In particular with dark decors 10, this edge 29 is less desirable, in view of the fact that it mostly will show as a white line.

FIG. 13 shows that the mostly lighter-colored edge 29 of the floor panel 1 can be colored in order to thereby exclude a possibly disturbing effect. According to FIG. 13, this simply is performed by means of a felt-tip pen 30 or the like.

FIG. 14 shows a floor panel 1 with a cut-away edge portion 31 in the form of a beveled edge, in this case, an inclination below 45°. This cut-away edge portion 21 preferably has a dimension H1 in horizontal direction that is smaller than 3 mm and still better is smaller than 2 mm, whereas the indicated height H2 preferably is larger than 1 mm, however, on the other hand preferably also is smaller than 3 mm and still better is smaller than 2 mm.

In FIG. 14, the surface of the cut-away edge portion is provided with a covering 32 obtained, for example, by means of transfer printing. As explained in the introduction, to this aim also other decorative layers, such as lacquer or the like, can be used.

FIG. 15 represents a variant of the cut-away edge portion 31.

Such cut-away edge portions 31 can be provided at one or more edges 5A-5B-6A-6B of the floor panel 1.

FIG. 16 shows, strongly schematized, a floor panel 1, whereby the coupling means 7, in this case, the groove 33, vary in height in respect to the basic board 9, this as a result of a terrace-shaped impressed zone 18A in the edge area of the floor panel 1, said zone having such a large length L that, when forming the groove 33, the floor panel 1 locally has moved up and down. In practice, this will happen with lengths L that are larger than 10 cm. Unexpectedly, it was found that, notwithstanding the non-straight course of the groove 33, such floor panels still can be coupled to each other quite well, without any substantial problem to turn or to snap them into each other. This fact then also forms the basis for the aforementioned second aspect of the invention explained in the introduction and claimed in the claims, whereby it is clear that this second aspect is not limited to imitations of flaky kinds of stone.

FIG. 17 shows a variant of the floor panel 1 of FIG. 16, whereby the coupling means 7, globally seen, slope towards one side of the floor panel 1, as the impression 18A, globally seen, is also performed downward-inclined towards one extremity of the floor panel 1.

In the top layer 11, in a known manner products, such as corundum or the like, can be incorporated in order to enhance the scratch and wear resistance of the surface of the floor panel 1. In order to enhance the wear resistance of the floor panel 1, it is also advantageous to use a relatively heavy overlay 14, preferably an overlay 14 with a weight of the carrier of at least 80 grams per square meter, preferably still in combination with hard particles, such as corundum, which latter then are situated, for example, at the upper side of the overlay 14.

It is noted that the printed decor 10 does not necessarily have to consist of a print on a carrier 15 that is impregnated with resin. So, for example, it is also possible to work with a print that is printed directly on the basic board 9, whether or not by the intermediary of additional layers, such as primers or the like, whereby the top layer 11 then is formed by a layer of synthetic material, in which the impressions 18 are formed, said layer being provided over the decor 10 in any manner.

Finally, it is noted that in a deviating form of embodiment of the invention, the decor 10, instead of imitating a slate or another flaky kind of stone, also may have a fashion pattern, whereby, for example, the aforementioned terrace-shaped impressions 18 simply are provided over a monochrome, brightly colored decor 10.

The aforementioned terraces preferably are limited by clearly outlined transitions extending along the entire periphery, or, at the location where the floor panel terminates, by the respective edge of the panel.

By the “upper edge” intended in the second and third aspects, the edge 34, indicated in FIGS. 13 and 14, of the top layer 11 is meant. By the largest value intended in the third aspect, the value is meant that is indicated by W in FIGS. 13 and 14.

The present invention is in no way limited to the forms of embodiment described by way of example and represented in the figures; on the contrary, such floor panels may be realized according to various variants, without departing from the scope of the invention. 

1. Floor panel, comprising a decor, as well as a top layer on the basis of synthetic material, and wherein the upper side of the floor panel imitates slate or another flaky kind of stone, further wherein the floor panel comprises terrace-shaped impressions at its upper side.
 2. Floor panel according to claim 1, wherein the decor represents a pattern that is realized as a function of the kind of stone to be imitated.
 3. Floor panel according to claim 1, wherein the printed decor comprises shadow lines and/or transition lines following at least partially the contour of a flake of the imitated kind of stone.
 4. Floor panel according to claim 1, wherein the terrace-shaped impressions are at least partially corresponding to a pattern represented by the decor.
 5. Floor panel according to claim 1, wherein the terrace-shaped impressions comprise terraces, which are substantially situated in planes that are substantially parallel to the plane in which the floor panel extends, such that the terraces form zones that are realized from terrace to terrace at a different depth.
 6. Floor panel according to claim 1, wherein the terrace-shaped impressions are obtained as the result of a press treatment with a press plate, the latter having obtained a terraced surface by means of several etching treatments.
 7. Floor panel according to claim 1, wherein the terrace-shaped impressions are obtained as a result of a press treatment with a press plate, in which partially overlapping portions have been etched away and that, in these etching treatments as such, one works with two or more different etching depths (E1-E2), such that the number of different heights, at which impressed terraces are situated on the floor panel, is larger than the number of etching treatments performed on the press plate.
 8. Floor panel according to claim 7, wherein the terrace-shaped impressions are the result of an embossment with a press plate, on which at least five and still better at least eight etching treatments have been performed, and further wherein at least a number thereof, as such, has been realized with different etching depths.
 9. Floor panel according to claim 1, wherein the terrace-shaped impressions that are formed by successive step-wise transitions, such that the surface of the zones lying in between as such changes in height, such that the height difference between two successive terrace edges is smaller than the height difference at the location of a transition, and preferably is zero or almost zero.
 10. Floor panel according to claim 1, wherein the panel shows at least two zones of different gloss degree, so that each of the zones substantially corresponds to a visible portion of a flake of the imitated kind of stone.
 11. Floor panel according to claim 1, wherein the imitation of the flaky stone continues over the entire floor panel, possibly with the exception of the edges of the floor panel, whereby the floor panel then imitates a single tile.
 12. Floor panel according to claim 1, wherein the panel comprises cut-away edge portions at one or more edges, so that the surface formed by said cut-away edge portions is colored, for example, by means of a covering applied by means of transfer printing, or by means of a coloring agent, for example, a coloring agent applied by means of a felt-tip pen, a lacquer or the like.
 13. Floor panel according to claim 1, said panel comprising at least at two opposite edges, and in the case of a rectangular floor panel, whether oblong or square, preferably at all edges, coupling means, which, in the coupled condition of two of such floor panels, effect a vertical and horizontal locking.
 14. Floor panel according to claim 13, wherein height differences occur along the upper edge of the floor panel as a result of the terraced construction, and in that along these upper edges impressed zones are present and that all these zones along the edges are limited to distances that are smaller than 10 centimeters.
 15. Floor panel, comprising a single-layer or multi-layer or single- or multipartite substrate, a decor, as well as a top layer on the basis of synthetic material, wherein impressed zones are present on the upper side of the floor panel, said zones extending along at least a part of at least one upper edge of the floor panel and that the floor panel, at least at the edge where said upper edge is situated and at an opposed edge, is provided with mechanical coupling means allowing to couple two of such floor panels to each other, which coupling means thereby can effect a locking in vertical and horizontal directions; and that these coupling means are the result of a machining treatment, so that the upper side of the floor panel is used as a reference, whereby the location of the coupling means as a result of the impressed zones fluctuates in height in respect to the substrate.
 16. Floor panel according to claim 15, wherein the floor panel, at the upper edge, is provided with a cut-away edge portion that is colored.
 17. Floor panel, comprising a single-layer or multi-layer or single- or multipartite substrate, a decor, as well as a top layer on the basis of synthetic material, and wherein the floor panel, at least at two opposite edges is provided with mechanical coupling means allowing to couple two of such floor panels to each other, which coupling means thereby can effect a locking in vertical and horizontal directions; wherein at the upper side of the floor panel at least one impressed zone is present that is situated along an upper edge of at least one of the aforementioned two opposite edges of the floor panel; and wherein this impressed zone shows an impression which, at least on the upper edge, effects a height difference with as the largest value at least 0,1 mm; and that this impressed zone extends along said upper edge over a distance of at least 10 centimeters.
 18. Method for manufacturing a floor panel, of the type that is intended for forming a floating floor covering, wherein the floor panel comprises a basic board with at the upper side a top layer on the basis of synthetic material with impressions, and further wherein the impressions are applied during a press treatment with a press plate, on which at least five and still better at least eight etching treatments have been performed, so that at least a number of which, as such, have been performed with differing etching depths and at least a number have been performed partially overlapping. 